Arming switch



June 4, 1963 J. BROTHERS 3,092,697

ARMING SWITCH Filed Sept. 14, 1961 ff gf/ /i I I 2 29 2f 74 l Z 2 n? 5.26 f 6 I 2o f7 I, Q-e/ ,2 4 l/ l v INVENTOR. Jack Ercher's United StatesPatent O 3,092,697 ARMING SWITCH Jack Brothers, Succasunna, NJ.,assigner to the United States of America as represented by the Secretaryof the Army Filed Sept. 14, 1961, Ser. No. 138,203 3 Claims. (Cl.2ML-61.53) (Granted under Title 35, U.S. Code (1952), sec. 266) Theinvention described herein may be manufactured `and used by or for theGovernment for governmental purposes without the payment to me of `anyroyalty thereon.

This invention relatm to an `arming switch, `and more particularly to anarming switch for closing an arming circuit or the like in a projectilefuze.

The present invention consists of a contact body with a movable camslider detented by pins which .are released by centrifugal force.Cylinders, moved radially by centrifugal force propel the earn slidertowards armed position and a spring loaded electrical contact o-n theforward end of the cam slider makes contact with :a iixed electricalcontact to complete an arming `circuit in the fuze.

It is a primary object of this invention yto provide an arming switchthat is operated by centrifugal force due to projectile spin. Y

It is mother object of the invention to provide a switch in which amovable cam slider carrying a `spring biased contact is released by apair of, spring biased detents responsive to centrifugal torce to moveforward and cause the spring biased contact -to abut a iixed contact andcomplete an arming circuit in la fuze.

It is 4 another object to provide 1an yarming lock to prevent -the camslider from returning to an unarmed position, once .released therefrom.

It, is still 'another object to provide an .arming switch having axialsymmetry in the armed position and possessing advantages over plungertype .arming switches that cause a lateral load which is difficult toovercome in gnaze action.

It is a final object of the invention .to provide an arming switch thatlis compact and simple in yoper-ation.

The specific nature of the invention as well las other objects `andadvantages thereof, will :clearly 'appear from a description of apreferred embodiment as shown in the accompanying drawing in which:

FIG. 1 is a cross sectional view of the arming switch of the inventiontaken along line 1-1 of FIG. 5, the switch being locked in unarmedposition, and a projectile being indicated in broken lines;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a fragmentary sectional view showing the switch being inunlocked and armed position, the plane of the section being similar tothat of FIG. 2;

FIG. 4 is a view similar to FIG. 3 but showing the plane of the sectionas in FIG. 1;

FIG. 5 is a plan view taken along a plane as indicated by line 5 5 ofFIG. 1;

FIG. 6 is a perspective view of one of the rollers;

FIG. 7 is a perspective view of the cam slider; and

FIG. 8 is a sectional view of the contact body taken on line SS of FIG.5.

Referring to the drawing, reference character 1 indicates a housinggenerally, which is externally threaded as at 2 and 3 for attachment tothe base well of a projectile or the like indicated by broken lines, 4.

Body 1 is provided with a well 5.

An insulating sleeve 6 is fitted in well 5.

A contact body 7 is fitted within sleeve 6 and rests on an insulatingwasher 8 at the bottom of well 5.

3,092,697 Patented June 4, 1963 ICC `flat plate having a thicknesssubstantially equal to the Width of slot 9 in contact body 7 to allowslider 14 to slide therein.

Slider 14 is provided with a reduced lower portion 15 which is notchedat its sides at 16 and 17 and at its bottom as at 18.

An axial bore 19 is provided at the upper portion of slider 14 and alsoa transverse bore 20 is provided in the reduced portion 15.

Notches 16 and 17 forming camming surfaces receive rollers 21 which rideon inclined camming surfaces 12 and 13.

Notch 18 receives a plastic arming lock 22 which also is cylindrical inshape.

Bore 11 in contact body 7 receives a pair of plunger detents 23 whichare biased inwardly by coil springs 24.

Axial bore 19 in slider 14 receives a switch contact 25 and a setbacksleeve 26 which are biased in opposite directions by a coil spring 27.In-turned portions 28 at the 'orice of bore 10 prevent switch contact 25and sleeve 26 from displacement from bore 10.

Arranged above and contacting contact body 7 is a contact washer 29. y

An insulating washer 30 is mounted on top of washer 29.

Both washers 29 and 30 are provided with central openings 31 and 32 anda yxed contact 33 protrudes through openings 31 and 32 and is alignedwith con tact 25. v

A pin 34`entering fuze body 1, sleeve 6 and contact body 7, preventsmovement of the parts during handling, prior to assembly. When theswitch is assembled to the fuze, pin 34 is no longer functional.

Fixed contact 33 may be connected to an electric detonator (not shown)in an explosive powder train (also not shown) of the fuze.

The other side of the circuit is connected to the contact washer 29which may be connected to a power source.

First, safety pin 34 is removed.

When the projectile 4 starts to accelerate, such as when tired from agun (not shown), setback forces will force all movable parts towards therear, momentarily holding Ithe cam slider 14 tightly against the fuzebody 1 as seen in FIG. 1 and therefore shorting slider 14 to fuze body1.

When projectile 4 starts to spin due to riiiing in the barrel of the gun(not shown), centrifugal force will be applied on all parts of thearming switch.

After set back has decayed to a certain value, centrifugal force willovercome the set back force and plunger detents 23 will separate andpermit cam slider 14 to be moved forwardly by rollers 21 which rideoutwardly upon inclined surfaces 12 and 13 and the wall of notches 16and 17.

`Contact 25 will be pressed against tixed contact 33 to close the switchand maintain a positive contact.

Arming lock 22 will also move radially from the central position shownin FIGURE 2 under contact body 7 to prevent the return of cam slider 14and shorting of the switch.

Use of the switch of the invention is not necessarily limited tocompleting an electrical circuit, but could be altered to be used in afuze using a stab type detonator.

Contact 25 could be a ring pin used to detonate a primer or other firingelement if desired.

Variations and modifications may be effective without departing from thescope of the novel concept of the present invention as set forth in theappended claims.

What is claimed is:

1. An arming switch for a projectile fuze comprising an externallythreaded body for attachment to the projectile, 'there being an axialwell in said body; an insulating sleeve litted within said well; a`contact body fitted within said sleeve, there being a diametrical slotin said contact body; a cam slider slidably mounted in said slot; aspring biasedv switch contact in said slider; a fixed contact disposedon the outer side of said contact body; a first means for normallylocking said slider in an unarmed position within said slot, comprisinga transverse bore in the inner portion of said contact body, atransverse bore in the inner portion of said slider and a pair ofinwardly biased detents slidably mounted in said transverse bore in saidcontact body and normally entering said transverse bore in said sliderwhen said slider is in an unarmed position in said slot, said detentsseparating outwardly upon projectile spin to leave said transverse borein said slider and free said slider for outward movement in said slot; asecond means in said contact body for moving said slider outwardly insaid slot to press said switch contact in saidV slider into contact withsaid fixed;

switch contact and a third means for preventing the return of said camslider to its unarmed position in said slot.

2. An arming switch for a projectile fuze comprising an externallythreaded body for attachment to the projectile, there being an axialwell in said body; an insulating sleeve fitted within said well; acontact body fitted within said sleeve, there beingY a diametrical slotin said contact body; a cam slider slidably mounted in said slot; aspring biased switch contact in` said slider; a fixed contact disposed`on the outer side of said contact body; a first means for normallylocking said slider in an unarmed position Within said slot; a secondmeans in said contact body for moving said slider outwardly in said slotto press said switch contact in said slider into contact with said fixedswitch contact, said second means comprising a reduced inward portion onsaid slider; a pair of diametrically disposed notches formed by theintersection between the reduced inner and outer portion of said slider,there being a pair of diametrically opposed, outwardly inclined camsurfaces formed on the oor of said slot in said slider and a pair ofrollers in said slot normally retained by said notches and riding onsaid inclined surfaces, said rollers being arranged, one each in a saidnotch, said rollers riding outwardly upon projectile spin to move saidslider outwardly in said slot; and a third means for preventing saidslider from returning to its unarmed position in said slot.

3. An arming switch for a projectile fuze comprising an externallythreaded body for attachment to the projectile, there being an axialwell in said body; an insulating sleeve fitted within said Well; acontact body fitted within said sleeve; there being a diametrical slotin said contact body; a cam slider slidably mounted in said slot; aspring biased switch contact in said slider; a fixed contact disposed onthe outer side of said contact body; a rst means for normally lockingsaid slider in an unarmed position within said slot; a second means insaid contact body for releasing said slider whereby said first meanswill move said slider outwardly in said slot to press said switchcontact in said slider into Contact with said xed switch contact; and athird means for preventing said slider from returning to its unarmedposition in said slot comprising a notch having beveled edges in theinner edge of said slider; a roller in said notch and riding on thefloor of said well in said body, said roller moving radially uponprojectile spin to ride under said slider and prevent its return to theunarmed position in said slot.

References Cited in the file of this patent UNITED' STATES PATENTS2,671,832 Hansard et al. Mar. 9, 1954 2,898,416 Clurman Aug. 4, 19592,997,883 Wilkes Aug. 29, 1961 3,038,973 Alpert June 12, 1962

1. AN ARMING SWITCH FOR A PROJECTILE FUZE COMPRISING AN EXTERNALLYTHREADED BODY FOR ATTACHMENT TO THE PROJECTILE, THERE BEING AN AXIALWELL IN SAID BODY; AN INSULATING SLEEVE FITTED WITHIN SAID WELL; ACONTACT BODY FITTED WITHIN SAID SLEEVE, THERE BEING A DIAMETRICAL SLOTIN SAID CONTACT BODY; A CAM SLIDER SLIDABLY MOUNTED IN SAID SLOT; ASPRING BIASED SWITCH CONTACT IN SAID SLIDER; A FIXED CONTACT DISPOSED ONTHE OUTER SIDE OF SAID CONTACT BODY; A FIRST MEANS FOR NORMALLY LOCKINGSAID SLIDER IN AN UNARMED POSITION WITHIN SAID SLOT, COMPRISING ATRANSVERSE BORE IN THE INNER PORTION OF SAID CONTACT BODY, A TRANSVERSEBORE IN THE INNER PORTION OF SAID SLIDER AND A PAIR OF INWARDLY BIASEDDETENTS SLIDABLY MOUNTED IN SAID TRANSVERSE BORE IN SAID CONTACT BODYAND NORMALLY ENTERING SAID TRANSVERSE BORE IN SAID SLIDER WHEN SAIDSLIDER IS IN AN UNARMED POSITION IN SAID SLOT, SAID DETENTS SEPARATINGOUTWARDLY UPON PROJECTILE SPIN TO LEAVE SAID TRANVERSE BORE IN SAIDSLIDER AND FREE SAID SLIDER FOR OUTWARD MOVEMENT IN SAID SLOT; A SECONDMEANS IN SAID CONTACT BODY FOR MOVING SAID SLIDER OUTWARDLY IN SAID SLOTTO PRESS SAID SWITCH CONTACT IN SAID SLIDER INTO CONTACT WITH SAID FIXEDSWITCH CONTACT AND A THIRD MEANS FOR PREVENTING THE RETURN OF SAID CAMSLIDER TO ITS UNARMED POSITION IN SAID SLOT.